B2278

THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function): B2278: Engine Switch Circuit Malfunction

DTC B2278 - Engine Switch Circuit Malfunction

DESCRIPTION

This DTC is output when 1) a malfunction is detected between the main body ECU (instrument panel junction block) and the engine switch; or 2) either of the switches inside the engine switch is malfunctioning.
HINT: When the main body ECU (instrument panel junction block) is replaced with a new one and the cable from the negative (-) battery terminal is connected, the power source mode becomes the IG-ON mode. When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

After the main body ECU (instrument panel junction block) is replaced, perform the registration procedures for the engine immobiliser system Engine Immobiliser System (W/ Smart Key System).






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (START SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Check the Data List for proper functioning of the start switch.
HINT: When using the Techstream with the engine switch off, turn on and off any of the door courtesy light switches repeatedly at 1.5 second intervals or less until communication between the Techstream and vehicle starts.

Main Body





OK:
ON (engine switch is pushed) and OFF (engine switch is not pushed) appear on the screen.
NG -- INSPECT ENGINE SWITCH
OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)
2. INSPECT ENGINE SWITCH
(a) Remove the engine switch Removal.




(b) Disconnect the switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





HINT: This switch is a momentary type switch.

NG -- REPLACE ENGINE SWITCH
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)
(a) Disconnect the E51 ECU connector.




(b) Disconnect the E38 switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)
OK -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)